Numerical investigation of mixing efficiency of helical ribbons

AIChE Journal ◽  
1998 ◽  
Vol 44 (4) ◽  
pp. 972-977 ◽  
Author(s):  
J. de la Villéon ◽  
F. Bertrand ◽  
P. A. Tanguy ◽  
R. Labrie ◽  
J. Bousquet ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Mixing Efficiency

Three Dimensional Triangle Chaotic Micromixer

2014 ◽  
Vol 875-877 ◽  
pp. 1189-1193 ◽  
Author(s):  
Lin Li ◽  
Qing De Chen ◽  
C.T. Tsai
Keyword(s):  
Numerical Investigation ◽  
Three Dimensional ◽  
Microfluidic System ◽  
Chaotic Advection ◽  
Mixing Efficiency ◽  
Mixing Index ◽  
Ansys Fluent ◽  
Essential Component ◽  
Highly Efficient

Micromixer is essential component of microfluidic system which has wide application in the field of chemistry and biochemistry. A highly efficient and easily fabricated three dimensional micromixer based on chaotic advection is proposed and investigated. The depth of 25μm for each layer of micromixer and two kinds of fluids, which have viscosities of 0.00097kgm-1s-1and 0.186kgm-1s-1with Re number from 0.001 to 150, are adopted for numerical investigation of mixing efficiency by using ANSYS-Fluent. High mixing index of more than 90% can be obtained by using less than 300μm of length under Re number of 0.01 for mixing Fluid 1. However, it requires 850μm to achieve mixing index of more than 90% for hard-to-mix Fluid 2.

scholarly journals Numerical Investigation of Liquid–Liquid Mixing in Modified T Mixer with 3D Obstacles

2021 ◽  
pp. 25-32
Author(s):  
Md. Readul Mahmud
Keyword(s):  
Numerical Investigation ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Channel Length ◽  
Navier Stokes ◽  
Mixing Efficiency ◽  
Mixing Performance ◽  
Wide Range

The fluids inside passive micromixers are laminar in nature and mixing depends primarily on diffusion. Hence mixing efficiency is generally low, and requires a long channel length and longtime compare to active mixers. Various designs of complex channel structures with/without obstacles and three-dimensional geometries have been investigated in the past to obtain an efficient mixing in passive mixers. This work presents a design of a modified T mixer. To enhance the mixing performance, circular and hexagonal obstacles are introduced inside the modified T mixer. Numerical investigation on mixing and flow characteristics in microchannels is carried out using the computational fluid dynamics (CFD) software ANSYS 15. Mixing in the channels has been analyzed by using Navier–Stokes equations with water-water for a wide range of the Reynolds numbers from 1 to 500. The results show that the modified T mixer with circular obstacles has far better mixing performance than the modified T mixer without obstacles. The reason is that fluids' path length becomes longer due to the presence of obstacles which gives fluids more time to diffuse. For all cases, the modified T mixer with circular obstacle yields the best mixing efficiency (more than 60%) at all examined Reynolds numbers. It is also clear that efficiency increase with axial length. Efficiency can be simply improved by adding extra mixing units to provide adequate mixing. The value of the pressure drop is the lowest for the modified T mixer because there is no obstacle inside the channel. Modified T mixer and modified T mixer with circular obstacle have the lowest and highest mixing cost, respectively. Therefore, the current design of modified T with circular obstacles can act as an effective and simple passive mixing device for various micromixing applications.

Numerical Investigation of Liquids Mixing in Pin-Finned Microchannels

2012 ◽  
Author(s):  
Haleh Shafeie ◽  
Omid Abouali ◽  
Khosrow Jafarpur ◽  
Goodarz Ahmadi
Keyword(s):  
Differential Equation ◽  
Mass Transport ◽  
Computational Model ◽  
Numerical Investigation ◽  
Stokes Equations ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Mixing Efficiency ◽  
Navier Stokes Equations ◽  
Pin Fins

In the present work, the performance of pin-finned microchannels as the micromixers is investigated. Different patterns for distribution of pin-fins were examined (staggered and oblique distribution of fins). A 3-D computational model was developed and the Navier-Stokes equations were solved and the corresponding flow fields were evaluated. The mass transport differential equation was also solved and the concentration of liquids in the mixture was evaluated. The results for the mixing efficiency were compared between the simple and pin-finned microchannels. The results suggest that the finned microchannels with staggered distribution of pins perform very well in mixing of liquids. The mixing efficiency reaches to 100 percent for the Reynolds numbers in which the mixing efficiency is less than 10 percent for the simple microchannels.

Experimental and Numerical Investigation into Mixing Efficiency of Micromixers with Different Geometric Barriers

2006 ◽  
Vol 505-507 ◽  
pp. 391-396 ◽  
Author(s):  
Chia Yen Lee ◽  
Chiufeng Lin ◽  
M.F. Hung ◽  
R.H. Ma ◽  
Chien Hsiung Tsai ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Numerical Investigation ◽  
Low Cost ◽  
Experimental Results ◽  
Mixing Efficiency ◽  
Mixing Performance ◽  
Side Channels ◽  
Liquid Samples ◽  
Glass Slides ◽  
Good Agreement

This paper proposes a numerical and experimental investigation of mixing behaviors of two liquid samples in microchannels that are shaped into different geometric barriers. The micro-mixers utilized in this study are fabricated on low-cost glass slides using a simple and reliable fabrication process. Samples are driven by a hydrodynamic pump to lead them into the mixing section of the microchannels. The effects of mixing performance of various kinds of barrier shape are discussed in this study. The numerical and experimental results show that a better mixing efficiency can be obtained in the microchannels while using the elliptic-shape barriers in compare with the leaking side-channels. In this study, the simulated and experimental results are in good agreement. The investigation of mixing efficiency in microchannels with different geometric barriers could be crucial for microfluidic systems.

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